Studies consistently show that juvenile sex offenders (JSO's) are a heterogeneous population, such that generalizability and interpretation of results are difficult. JSO's are commonly diagnosed with comorbid conditions such as conduct disorder, attention-deficit hyperactivity disorder, antisocial personality disorder, narcissistic personality disorder, learning disabilities, affective disorders, post- traumatic stress disorder, and substance abuse. The population of JSO's must be further defined by using standardized instruments to specify populations when performing treatment outcome studies. Generally, assessment instruments that show reliability and validity are few, although several measures appear promising. Although some measures with adequate reliability target sexual interest, the validity of such inventories is lacking. Assessment instruments specific to sexual deviance must be developed. Treatment procedures for this population are in the early stages. Few studies have evaluated the clinical utility of interventions for use with JSO's, and JSO interventions are largely extrapolations from the adult literature. Insight-oriented therapies have not been effective, and there is a possibility that pharmacological treatment could cause detrimental changes in the physiological developments of adolescents. Preliminary findings suggest that the most promising interventions may be a combination of behavioral, psycho-educational, and supportive therapies, with an emphasis on family counseling. 88 references